PROJECT SUMMARY The 2020 Gordon Research Conference (GRC) on ?Thiol-Based Redox Regulation and Signaling? will provide a forum for junior and senior scientists from many disciplines to share unpublished, innovative research about biological processes that are regulated by redox-based post-translational modifications of cysteine-containing proteins, and associated disorders. This biennial meeting was established in 2006 under the auspices of the GRC, an organization internationally known for the high quality, cutting edge nature of its meetings. The specific objectives are to foster interactions across disciplines, promote a sense of community among cysteine-focused researchers, provide a springboard into redox biology research for scientists from other fields, and mentor students in a supportive scientific setting. The invited speakers include both prominent scholars and promising young scientists who are applying new approaches to the redox sciences and other intersecting fields. In addition to the 40 invited speakers, all participants can present their research at highly interactive poster sessions; from these, we select 10 short talks that are interleaved in each session. A distinct feature of this meeting is its association with a student-organized Gordon Research Seminar (GRS). The GRS assembles ~45 graduate and postdoctoral trainees to present and discuss their research immediately before the GRC begins. A few senior investigators are invited to the GRS to provide advice and feedback, thereby nurturing the careers of our future principal investigators. Prior GRC/GRS meetings garnered exceedingly positive reviews for focusing on the most recent findings, and promoting an informal, highly interactive format. The 2020 GRC on ?Thiol-Based Redox Regulation and Signaling? will be held July 12-17, 2020 at the Rey Don Jaime Grand Hotel in Castelldefels, Spain, an ideal international setting for encouraging intense and invigorating discussions in a collegial atmosphere. The GRS will be held July 11-12, 2020. A guiding principle that will serve to keep this conference fresh and relevant is our commitment to explore novel themes, and to gather a completely new cast of speakers, for each successive meeting. The specific program described in this application has the overarching goals of representing the breadth of thiol-based redox regulation sciences, while also establishing a set of thematic foci. Thus, the 2020 meeting will emphasize research areas that extend beyond the thiol-based or ?cysteine centric? proteome in an effort to introduce new concepts for discussion. We will consider the related field of methionine oxidation, selenoproteins research, and the influence of redox metabolites on human health and disease. Finally, the meeting will integrate clinically relevant research, including novel strategies to target the redox vulnerabilities of cancer cells. Here, basic research findings will dovetail with the latest information on sulfur- and selenium-based modifications, reduction, and central regulatory mechanisms. The 2020 GRC/GRS meetings will provide participants with an ideal setting to explore how research approaches at very different levels relate to one another, facilitating new ideas and collaborations.